Local block relaxation method for the solution of equations of gasdynamics

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 1377-1384
Author(s):  
Carlo de Nicola ◽  
Renato Tognaccini ◽  
Vittorio Puoti
Keyword(s):  
Relaxation Method ◽  
Solution Of Equations ◽  
Block Relaxation ◽  
Local Block

Local Block Relaxation Method for the Solution of Equations of Gasdynamics

AIAA Journal ◽  
2000 ◽  
Vol 38 (8) ◽  
pp. 1377-1384 ◽  
Author(s):  
Carlo de Nicola ◽  
Renato Tognaccini ◽  
Vittorio Puoti
Keyword(s):  
Relaxation Method ◽  
Solution Of Equations ◽  
Block Relaxation ◽  
Local Block

scholarly journals Multiple Soft Fault Diagnosis of Bjt Circuits

2014 ◽  
Vol 21 (4) ◽  
pp. 663-674 ◽  
Author(s):  
Michał Tadeusiewicz ◽  
Stanisław Hałgas
Keyword(s):  
Fault Diagnosis ◽  
Diagnostic Test ◽  
Analog Circuits ◽  
Relaxation Method ◽  
Bipolar Transistors ◽  
Strongly Nonlinear ◽  
Soft Fault ◽  
Soft Fault Diagnosis ◽  
Nonlinear Analog Circuits ◽  
Block Relaxation

Abstract This paper deals with multiple soft fault diagnosis of nonlinear analog circuits comprising bipolar transistors characterized by the Ebers-Moll model. Resistances of the circuit and beta forward factor of a transistor are considered as potentially faulty parameters. The proposed diagnostic method exploits a strongly nonlinear set of algebraic type equations, which may possess multiple solutions, and is capable of finding different sets of the parameters values which meet the diagnostic test. The equations are written on the basis of node analysis and include DC voltages measured at accessible nodes, as well as some measured currents. The unknown variables are node voltages and the parameters which are considered as potentially faulty. The number of these parameters is larger than the number of the accessible nodes. To solve the set of equations the block relaxation method is used with different assignments of the variables to the blocks. Next, the solutions are corrected using the Newton-Raphson algorithm. As a result, one or more sets of the parameters values which satisfy the diagnostic test are obtained. The proposed approach is illustrated with a numerical example.

Data-parallel line relaxation method for the Navier-Stokes equations

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 1603-1609 ◽  
Author(s):  
Michael J. Wright ◽  
Graham V. Candler ◽  
Deepak Bose
Keyword(s):  
Stokes Equations ◽  
Relaxation Method ◽  
Parallel Line ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Data Parallel

The Influence of Radiation on Arc Constriction in the Anode Region

1975 ◽  
Vol 97 (1) ◽  
pp. 41-46 ◽  
Author(s):  
E. Pfender ◽  
J. Schafer
Keyword(s):  
Analytical Model ◽  
Atmospheric Pressure ◽  
High Intensity ◽  
Radiation Effects ◽  
Relaxation Method ◽  
Anode Region ◽  
Conservation Equations ◽  
Radiation Losses ◽  
Argon Arcs

An improved analytical model for the description of the anode contraction zone of a high intensity arc takes radiation effects into account. The conservation equations for the anode contraction zone and the adjacent undisturbed arc column are solved numerically with a relaxation method. Results for atmospheric pressure argon arcs at three different currents demonstrate that radiation losses reduce temperature peaks substantially and, at the same time, provide a smooth matching of arc column and contraction zone solutions. Although the model seems to be adequate for a large portion of the anode contraction zone, the results indicate that refinements of the model are necessary for the region close to the anode, in particular, deviations from LTE have to be taken into account.

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